A man was arrested in Azusa -- a city just east of Pasadena where one of the largest fires in L.A. is raging -- Friday ... and, cops claim he may have tried to start another fire.

Azusa PD tells TMZ  ... officers were dispatched to a local park just before midnight in regards to a brush fire -- where they claim a witness told them the man who lit the fire was still at the scene.

Officers located the suspect -- a "transient" named Jose Carranza-Escobar -- who they claim admitted to lighting the fire. Cops then arrested Carranza-Escobar.

Los Angeles County Firefighters arrived and put out the blaze -- and, several other government departments are now assessing the extent of the damage caused by the fire.

Police have a "zero tolerance policy" for incidents like these ... so, it sounds like they plan to bring the hammer down on people who allegedly light fires in the area.

In fact, the L.A. County District Attorney has already assigned a prosecutor to the case from the arson unit ... and police tell us the evidence will be presented as soon as Monday for possible charges.

Azusa is approximately 16 miles east of Altadena ... the town devastated by the Eaton Fire -- a large blaze in northeastern L.A. that has burned more than 14K acres. It's the second-largest that broke out in L.A. this week -- about 10,000 acres smaller than the Pacific Palisades wildfire in West L.A.